Pool ladder lift



R. F. LOUGHRIDGE POOL LADDER LIFT May 7, 1963 Filed April 19, 1960 2 Sheets-Sheet 1 a ffwweg May 7, 1963 R. F. LOUGHRIDGE POOL LADDER LIFT 2 Sheets-Sheet 2 Filed April 19, 1960 m i V? f W m f %m m United States Patent 3,088,123 POOL LADDER LIFT Robert F. Loughridge, Fort Worth, Tex., assignor to Esco Elevators, Inc., Fort Worth, Tex., a corporation of Texas Filed Apr. 19, 1960, Ser. No. 23,271 Claims. (Cl. 4-172) My invention relates to hydraulic lifting devices, and more particularly to such devices designed especially for use in swimming pools and the like.

It is common practice to have fixed ladders located at strategic places in swimming pools to enable b-athers to climb out of the pool at will. However, one climbing up out of the water experiences the feeling that his weight is much greater than normal. For many people not in top physical condition, climbing a ladder to get out of the pool becomes a task. For older people, and

.those who have physical infirmities, climbing out of the pool can become sufficiently difficult to discourage them from swimming at all. Even for the young and most physically fit, the task of climbing out of the pool frequently (for example when diving) absorbs much of their energy. In addition to the difficulty and inconvenience encountered, climbing a fixed ladder out of a pool can be potentially dangerous. Loss of footing on the fixed ladder can result in painful and sometimes serious injury. It has occurred to me that there is a definite need for some kind of device which could be utilized in lieu of the fixed-type pool ladder and which would obviate the disadvantages, inconvenience, and potential dangers of same.

It is, accordingly, an object of my invention to provide a device which will enable a person to get out of a pool safely, conveniently, and with minimum expenditure of physical energy.

Another object of my invention is to provide a swimming pool lift which is capable of safely and conveniently lifting a person in upright position out of a pool into step-off position at bank level.

Another object of my invention is to provide an effective, safe, and practical hydraulic swimming pool ladder lift device.

Another objectof my invention is to provide a hydraulic swimming pool ladder lift which is self-contained, and requires no special auxiliary equipment.

These and other objects are effected by my invention, as well be apparent from the following description taken in accordance with the accompanying drawings, forming a part of this application, in which:

FIGURE 1 is .a perspective view of a swimming pool lift device in accordance with a preferred embodiment of my invention;

FIGURE 2. is a schematic perspective view, partly in phantom showing the device of FIGURE 1 installed in a pool and at its lower position;

FIGURE 3 is a schematic perspective view, partly in phantom, showing the device of FIGURE 1 in the process of lifting a person up out of the pool;

FIGURE 4 is a schematic section view showing details of the hydraulic cylinder and plunger portion of the device of FIGURE 1;

FIGURE 5 is a schematic view with parts broken away, showing the telescoping hydraulic fluid inlet connections, and conduit for the device of FIGURE 1;

FIGURE 6 is a schematic end elevational view of the lift step, its supports, and the step-actuated hydraulic fluid control valve;

FIGURE 7 is a schematic section view showing details of the hydraulic fluid control valve; and

FIGURE 8 is a schematic perspective view showing the 3,088,123 Patented May 7, 1963 back side of the toe plate and the structure to which the hydraulic plunger is mounted.

Referring now to the drawings, a swimming pool lift device in accordance with a preferred embodiment of my invention includes as major components a primary support structure 11, left and right rails 13, 15, hydraulic cylinder and plunger assembly 17, hydraulic control valve 18, step assembly 19, toe plate assembly 21, and telescoping hydraulic fluid inlet assembly 23.

The primary support structure 11 may be made of any suitable material, but is preferably made of fibreglass, which has the requisite strength and also cannot rust or corrode, and is almost immune to weathering. The primary support structure 11 has a back-board portion 25 which depends from the front edge of the landing portion 27 at right angles thereto. The back-board 25 and the landing 27 may be made as an integral unitary structure, as shown by the drawings, or it may be made in two pieces which are then joined and fixed, one to the other. The landing 27 presents a flat upper surface and is designed to be fixed by means not shown onto a template (not shown) which is in turn anchored to the surface adjacent to the pool edge. The back-board 25 is thus suspended into the pool substantially parallel to and spaced from the pool sidewall. This spacing is accomplished at the back-board upper end by side flanges 29 integral with and adjacent to the juncture of the backboard 25 and landing 27. The rear edges 31 of the flanges abut the pool sidewall. Spacing at the back-board lower end portion is accomplished by a standoif rod 33 which is fixed at one end to the back-board and has its free end abutting the pool sidewall.

The left and right rails 13, 15 are each preferably made of seamless steel tubing material and are generally trombone-shaped, having a relatively long rear portion 35 parallel to and spaced from a shorter front portion 37, with an integral inverted U-shaped portion joining the front and rear portions at their upper ends. The rail rear portions 35 are each supported for vertical reciprocating motion by a respective upper and lower rail guide 39, 41. The rail guides can be made of any suitable material, but are preferably brass. This upper guides 39 are fixed to the upper corner portions'of the back-board 25. The lower guides 41 are also fixed to the back-board 25 and are spaced directly below the upper guides at a sufficient distance to allow the desired degree oftravel for the rails 13, 15. Each guide 39, 41 is provided with a cylindrical opening for receiving the respective rail with an appropriate slidable fit.

The step assembly 19 and the toe-plate assembly 21 are both supported by the rails 13, .15 and are fixed to the rails for reciprocating motion therewith, as will be presently described. The stepassembly 19 comprises a backplate member 43, left and right support brackets 45, 47 and the step 49. The back-plate 43 may be made of any suitable material, but is preferably a rectangular metal plate. The support brackets 45, 47 are preferably flanged metal triangles. The support brackets 45, 47 are fixed adjacent the respective end portions of the back plate 43 by bolts 51, so that the upper surfaces of the bracket flange faces are flush with the upper surface of the backplate 43. The step 49 may be made of any suitable material, preferably fibre-glass, and is hinged at 53 adjacent its front edge to the top front surface portion of the brackets 45, 47 in a manner to allow suflicient movement of the step rear edge portion to actuate the plunger 55 of the hydraulic control valve 18. The toe-plate assembly is a unitary metal structure having a rectangular front 57, a sloping top 59, side flanges 61, and a reinforced rear flange 63. The side flanges 61 are provided with a plurality of bolt holes 65. A pair of flat generally crankshaped side brackets 67 made of heavy metal strap maa terial are fixed by bolts 69 to the side flanges 61 of the toe plate assembly 21. The rearwardly protruding upper ends of the side bracket 67 are fixed by bolts 71 to flange portions of respective rear rail clamps 73. The rear rail clamps are metal straps having a cylindrical portion for receiving the rail and mating flange portions which are drawn together to effect clamping. The forwardly protruding lower ends of the side bracket 67 are fixed by bolts to mating flange portions of respective front rail clamps 77. The front rail clamps 77 have a cylindrical portion for receiving the rail, and mating flange portions which are drawn together to effect clamping. In addition, the front rail clamps 77 are provided with a second flange at right angles to the mating flanges. The step assembly backplate 43 is fixed by bolts 79 at its end portions to the second flange of the respective front rail clamp 77 Thus, the step assembly 19 and toe-plate assembly 21 are fixed relative to each other and to the rails 13, 15, for reciprocating movement with the rails. The front rail clamps 77 are located at the lower end portion of the front rails 37, and the rear rail clamps 73 are arranged to reciprocate between the upper and lower rail guides 39, 41.

The step assembly 19 is powered for upward movement by the hydraulic cylinder and plunger assembly 17, which will now be described. The hydraulic cylinder 81 is preferably a length of pipe having external threads at both end portions. The lower end of the cylinder is closed water-tight by an internally threaded bottom cap 83. The upper end portion of the cylinder is provided with an internally threaded top cap 85, which also has a central internally threaded bore for receiving a plunger guide bushing 87. The top cap is provided with a plurality of openings 89, which will allow free passage of water to the cylinder interior. The plunger bushing 87 is preferably made of plastic material such as polyethylene, and is provided with a smooth central bore sized to received a cylinder plunger 91 with a suitable slidable fit. The cylinder plunger 91 is a length of heavy tubing having external threads at its upper and lower end portions. The lower end portion of the cylinder plunger is threaded into the internal threads of the central bore of a piston 93, which is in the form of a metal disc, having a peripheral groove for receiving a sealing ring 95. The piston 93 of course acts as a reoiprocable transverse closure within the cylinder 81 and movable coaxially with the cylinder central longitudinal axis.

The upper end portion of the cylinder plunger 91 is threaded into the lower end of a 90 degree type elbow fitting 97, the elbow being rigidly fixed (as by welding) to a mounting plate 99 which in turn is fixed by bolts 101 to the center portion of the rear flange 63 of the toeplate assembly 21. Thus, reciprocation of the cylinder plunger 91 will cause reciprocation of the step, toe-plate, and rail assembly 19, 21, 13, 15.

The upper end of the elbow 97 is connected via a fiexible conduit to a cylinder port 105 of the three-way hydraulic control valve assembly 18 (the control valve assembly being mounted on the upper rear center portion of the step assembly back plate member). In addition to the cylinder port 105, the hydraulic control valve 18 (see FIGURE 7) also has an inlet port 107, which is connected via a flexible conduit 109 to the outlet fitting 111 of the telescoping fluid inlet assembly 23, and a discharge port 113. The control valve plunger 55 actuates a two-position gate element 115. The control valve gate element 115 and ports 105, 107, 113 are arranged so that when the plunger 55 is in normal, or non-actuated position, the inlet port 107 is closed, and the cylinder port 105 is open to discharge port 113; and when the plunger 55 is in actuated position, the discharge port 113 is closed and the inlet port 107 is open to the cylinder port 105. The plunger 55 is norm-ally biased by a spring 117 to its nonactuated position.

The telescoping inlet assembly 23 (see FIGURE has a cylindrical outer jacket 119 and a concentric inner cylinder 121. The inner cylinder 121 extends a short distance beyond the jacket upper end, but does not extend all the way to the jacket lower end. The inner cylinder 121 is fixed relative to the jacket 119 by means of a spacer 123 located near the cylinder lower end, and a cap which serves as both a spacer and water-tight closure 125 at the jacket upper end. The spacer 123 is provided with openings to allow free flow of fluid through it. The jacket 119 has a fluid outlet fitting 111 near its upper end, which fitting is connected via a flexible conduit 109 to the control valve inlet port 107. The jacket 119 has external threads at its lower end which thread into a foot member closure 127 which is fixed to the lower end of the left rail rear portion 35. The inner cylinder 121 is adapted for receiving for slidable reciprocating motion, a pipe rod 129. The upper end portion of the cylinder 121 has external threads for receiving a threaded cap 131 which is provided with a suitable packing 133. The lower end of the pipe rod 129 carries a suitable reciprocable fluid tight seal 135. The upper end of the pipe rod is threaded into an elbow fitting 137 located at the upper portion of the back-board 25 and which is in turn connected to a suitable water supply source (not shown). The jacket 119 is made about the same length as the distance from the bottom of a rail rear portion 35 to the toeplate rear flange 63.

In the embodiment of the invention shown, it is contemplated that water will be utilized as the hydraulic fluid. This water may be supplied from any suitable source, as for example, the swimming pool utility water supply line, or the pool circulating pump line. The supply line pressure should preferably be not less than 30 p.s.1.

In operation, assume that the pool ladder lift device is at rest in its unloaded state and at the lower limit of the rail travel (as shown in FIGURE 2). In this condition, the control valve inlet port 107 is closed, but operating water pressure is present at the inlet port, the water being introduced via pipe rod 129 and cylinder 121 of the telescopic fluid inlet assembly 23, its jacket 119 and outlet fitting 111, and flexible conduit 109. At the same time, the control valve cylinder port is open to the discharge port 113, so that water may pass freely from within the hydraulic cylinder 81 via the plunger pipe 91, flexible conduit 103, and control valve 18, and into the pool.

A person desiring to be lifted up out of the pool simply grasps the rail front portion 37, and stands up on the step 49. The persons weight on the step causes the step to rotate slightly on its hinge 53, pressing the control valve plunger 55 downward to the actuated position, opening the valve inlet port 107 to the cylinder port 105 and closing the discharge port 113. The supply water then flows via flexible conduit 103 and through the plunger pipe 91 and into the cylinder 81 below the piston 93, and the water pressure acts on the piston 93 to cause it to travel upward, thus moving the plunger 91 upward also. As the plunger 91 moves upward, it lifts the step, toe-plate, and rail assemblies 19, 21, 13, 15; the rail rear portions 35 being confined by the rail guides 39, 41. This upward motion continues until the rear rail clamps 73 contact the upper rail guides 39 and the step, toe-plate, and rail assemblies are held by continued water pressure on the piston 93 in this upper-travel limit position for as long as the person remains standing on the step 49 to keep the control valve 18 in its actuated position. When at the upper-travel limit, the step 49 is in such position as to enable the passenger to conveniently step off onto the landing 27. When the passenger steps off, then the control valve plunger 55 is urged by the bias spring 117 back to its non-actuated position, closing the inlet port 107, and opening the cylinder port 105 to the discharge port 113. The water can now flow freely out of the cylinder 81 below the piston 93 and via the plunger 91, flexible conduit 103, and discharge port 113 into the pool. The unloaded weight of the step, toe-plate, and rail assemblies is sufiicient to move the piston 93 downward, expelling the water in the cylinder 81, until the device comes to rest at its lower travel limit when the rear rail clamps 73 contact the lower rail guides 41. The device is then ready for its next passenger.

It should be apparent from the foregoing that I have provided an effective pool lift device which will enable a person to get out of a pool safely, conveniently, and with minimum expenditure of physical energy. It is understood that the foregoing disclosure and the showings made in the drawings are merely illustrative of the principals of my invention, and are not to be interpreted in a limited sense. For example, there are a number of types of three-way control valves that could be utilized. Also, there are several water pressure supply arrangements that could be used. If the pool circulating supply were used, a valve arrangement would be provided to divert the circulation during operation of the lift. The circulating pump would need to be a type that would slip when the lift was at its upper travel limit position. If desired, a separate pump could be used to normally circulate pool water but develop pressure when the circulating path was closed. This arrangement would require only a simple open-close valve. Further, if desired, the hydraulic mechanism could be passengenactuated by means other than step relative movement. Various arrangements of hydraulic power mechanisms could be utilized. Also, if desired, the lift mechanism could be arranged so that it would carry a load down as well as up. Thus, while -I have shown my invention in only one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

I claim:

1. A swimming pool lift device comprising a unitary structure including a back-board portion and a landing portion, with said landing portion adapted for resting on the bank of a pool and said back-board portion depending from the landing portion down into the pool adjacent a pool sidewall; upper and lower rail guides fixed to said back-board portion and adapted for receiving rails and guiding them for reciprocating motion; a left and right rail assembly, each said assembly comprising a rear portion adapted for reciprocating motion within respective rail guides, and a front portion held in spaced parallel relation to said rear portion and adapted for use as lift passenger hand rails; a support structure mounted to said rails intermediate the rail rear portion length; a control valve mounted on said structure and having an actuator, an inlet port, a discharge port, and a cylinder port, and arranged so that in non-actuated position said inlet port is closed and said cylinder port is open to said discharge port, and in actuated position, said discharge port is closed and said inlet port is open to said cylinder port; a step mounted on such structure and arranged so that said valve is actuated by the weight of a passenger on said step; a hydraulic cylinder fixed to said hack-board with its longitudinal axis parallel to that of said rear rail portions, a piston in said cylinder, and a pipe plunger fixed at one end to said piston and supported for reciprocating motion within said cylinder; means fixing said pipe plunger adjacent its other end to said support structure; conduit means connecting said pipe plunger to said control valve cylinder port, and conduit means connecting said control valve inlet port to a water pressure source.

.2. A swimming pool lift device comprising a first support structure adapted for mounting adjacent a pool sidewall in fixed relation thereto; a hydraulic cylinder fixed to said support structure, a reciprocable pipe plunger carried by said cylinder and driven by a piston located within said cylinder; a reciprocable rail structure; means supporting said rail structure on said first support structure for reciprocable motion relative thereto; a second support structure fixed to said rail structure; a lift passenger step and passenger hand rail means mounted to said second support structure; means fixing the outer end portion of said pipe plunger to said second support structure; control valve means adapted for connection to a swimming pool water pressure source and to said pipe plunger; and means responsive to weight on said step for actuating said control valve to control said piston and elfect reciprocable motion of said pipe plunger and its load.

3. A swimming pool lift device comprising a unitary structure including a back-board portion and a landing portion, with said landing portion adapted for resting on the bank of a pool and said back-board portion depending from the landing portion down into the pool adjacent a pool sidewall; upper and lower rail guides fixed to said back-board portion and adapted for receiving rails and guiding them for reciprocating motion; a left and a right rail assembly, each said assembly comprising a tubular rear portion adapted for reciprocating motion within respective rail guides, and a tubular front portion held in spaced parallel relation to said rear portion for use as a lift passenger hand rail, said front and rear portions being joined at their upper ends by an integral inverted U-shaped portion; a support structure mounted to said rails intermediate the rail rear portion length; a lift passenger step mounted to said second support structure; hydraulic water pressure means for powering said support structure and rail assemblies for reciprocable motion, and means responsive to motion of said step relative to said support structure for controlling said hydraulic means.

:4. A swimming pool lift device comprising a first support structure adapted for mounting adjacent a pool sidewall in fixed relation thereto; a reciprocable rail structure; means supporting said rail structure on said first support structure for reciprocable motion through said support means; passenger hand rail means disposed in fixed spaced parallel relation to said rail structure and extending longitudinally thereof, a second support structure bridging between said rail structure and said hand rail means adjacent the lower ends thereof; a lift passenger step mounted to said second support structure; hydraulic means utilizing swimming pool water supply for powering said rail structure for reciprocable motion; and means responsive to motion of said step relative to said second support structure for controlling said hydraulic means.

5. A swimming pool lift device comprising a first support structure adapted for mounting adjacent a pool sidewall in fixed relation thereto; a reciprocable rail structure; means supporting said rail structure on said first support structure for reciprocable motion through said support means; passenger hand rail means disposed in fixed spaced parallel relation to said rail structure and extending longitudinally thereof, a second support structure bridging between said rail structure and said hand rail means adjacent the lower ends thereof; a lift passenger step mounted to said second support structure; hydraulic means utilizing swimming pool water supply for powering said rail structure for reciprocable motion; and passenger actuated means for controlling said hydraulic means.

References Cited in the file of this patent UNITED STATES PATENTS 

4. A SWIMMING POOL LIFT DEVICE COMPRISING A FIRST SUPPORT STRUCTURE ADAPTED FOR MOUNGING ADJACENT A POOL SIDEWALL IN FIXED RELATION THERETO; A RECIPROCABLE RAIL STRUCTURE, MEANS SUPPORTING SAID RAIL STRUCTURE ON SAID FIRST SUPPORT STRUCTURE FOR RECIPROCABLE MOTION THROUGH SAID SUPPORT MEANS; PASSENGER HAND RAIL MEANS DISPOSED IN FIXED SPACED PARALLEL RELATION TO SAID RAIL STRUCTURE AND EXTENDING LONGITUDINALLY THEREOF, A SECOND SUPPORT STRUCTURE BRIDGING BETWEEN SAID RAIL STRUCTURE AND SAID HAND RAIL MEANS ADJACENT THE LOWER ENDS THEREOF; A LIFT 